Chmod command
1) Role: linux and unix file permissions to call three levels: file owner / group / other. Use chmod can control how files are called by others. (Mainly modify folders, file permissions )
2) U represents the owner of the file, g represents the owner of the file of those who belong to the same group, o represents someone other than, a three represent both.
3) + to add permissions, - indicates remove permissions, = represents a unique set permissions.
4), or 4 R & lt represent read, w represents 2 or written, x represents 1 or executable, X is only when this file is a subdirectory or file has been set through the executable. (Rwx 7)
5) -c: If the file permissions have changed indeed, it shows the change action;
6) -f: If the file permissions can not be changed and do not display an error message.
7) -v: displays detailed information on permissions change.
8) -R: all files and subdirectories in the current directory the same change permissions (that is handed back to the way one by one to change)